1. Field of the Invention
This invention relates to methods and apparatus for muffling and handling exhaust gases and cooling fluids emitted from a marine engine.
2. Description of the Prior Art
Muffler systems for marine engines differ significantly from mufflers for automobiles, in that the marine engine passes a significant amount of cooling water through the exhaust manifold and into the muffler. This water is ejected into the exhaust system to cool the combustion gases and permit those gases to be discharged through the hull of the boat.
There have been a number of muffling systems developed in the past which are specifically directed to handling both exhaust gases and cooling fluids for marine engines. For example, in U.S. Pat. No. 4,713,029, Ford discloses an "Inverted Flow Marine Engine Exhaust Muffler" utilizing a single chamber, with an inverted tube extending laterally across the single chamber, and with means permitting the exhaust gases to pass through the water at the bottom of the chamber, upwardly through the inverted tube and thence outwardly from the apparatus.
In U.S. Pat. No. 3,296,997, Hoiby et al disclose an "Exhaust and Muffling System For Marine Engines" also formed of a single chamber and with an inverted tubular output into which the exhaust gases flow.
Other marine engine muffling systems are taught in the following United States patents: U.S. Pat. No. 4,184,566 to Baker et al; U.S. Pat. No. 3,431,882 to Irgens; U.S. Pat. No. 3,291,252 to Davis; and U.S. Pat. No. 1,065,707 to Montgomery. Additionally, other marine engine exhaust systems are disclosed in British Patents 344,735 and 23,980.
Other prior art of interest includes United States patents U.S. Pat. No. 2,961,059 to Blair; U.S. Pat. No. 1,759,679 to Backman; U.S. Pat. No. 1,076,571 to Hall; U.S. Pat. No. 1,074,267 to Kenney; U.S. Pat. No. 2,360,429 to Leadbetter; U.S. Pat. No. 2,498,979 to Bourne; U.S. Pat. No. 784,833 to Brush; U.S. Pat. No. 1,015,955 to Helder; U.S. Pat. No. 4,416,350 to Hayashi; as well as USSR patent 1,127,807.